<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        /* 并集选择器 */
        /* 应用场景：不用标签需要一样的样式 */
        div,
        p,
        span {
            color: red;
        }
    </style>
</head>

<body>
    <div>这是div</div>
    <p>这是段落标签</p>
    <span>这是行内块元素</span>
</body>

</html>